Substrate polishing apparatus and method of polishing substrate using the same

ABSTRACT

Provided is a substrate polishing apparatus that includes a polishing unit and a pad supporting member. The polishing unit includes a polishing pad polishing a substrate seated on a substrate supporting member, and a pad driving member moving the polishing pad. The pad supporting member is disposed at a side of the substrate supporting member to support a portion of a polishing surface the polishing pad without contacting the substrate when an edge of the substrate seated on the substrate supporting member is polished. Accordingly, the substrate polishing apparatus prevents the polishing pad from being inclined to the outer side of a substrate while an edge of the substrate is polished, thereby improving polishing efficiency and preventing the breakage of a substrate during a polishing process.

CROSS-REFERENCE TO RELATED APPLICATIONS

This U.S. non-provisional patent application claims priority under 35 U.S.C. §119 of Korean Patent Application No. 10-2009-0067936, filed on Jul. 24, 2009, the entire contents of which are hereby incorporated by reference.

BACKGROUND

The present disclosure herein relates to an apparatus and a method for manufacturing a semiconductor, and more particularly, to substrate processing apparatus and method for polishing and cleaning a semiconductor substrate in a single wafer processing manner.

In a general semiconductor device manufacturing process, a plurality of unit processes such as a deposition process, a photolithography process, and an etch process should be repeatedly performed to form and stack a thin film. These processes are repeated until desired predetermined circuit patterns are formed on a wafer. After the circuit patterns are formed, many irregularities are formed on a surface of the wafer. As semiconductor devices are now highly integrated and also multilayered in structure, the number of irregularities on a surface of a wafer and a height difference between the irregularities increase. As a result, due to the non-planarization of the surface of the wafer, defocus may occur in a photolithography process. Thus, to realize the planarization of the surface of the wafer, the wafer surface should be periodically polished.

Various surface planarization techniques have been developed for planarizing the surface of a wafer. Among these, a chemical mechanical polishing (CMP) technique is widely used because wide surfaces as well as narrow surfaces may be planarized with good flatness by using the CMP technique. A CMP apparatus is used to polish the surface of a wafer coated with tungsten or an oxide, by using mechanical friction and chemical abrasives, and very fine polishing is possible using the CMP apparatus.

When a polishing apparatus polishes a wafer, the polishing apparatus disposes the wafer on the top surface of a polishing pad, and then, presses and rotates the wafer to the polishing pad. Such a polishing apparatus includes a retainer ring surrounding a wafer to prevent an edge of a wafer from being excessively polished. However, since an expensive retainer ring is polished together with a wafer all through a wafer polishing process, a replacement cycle of the retainer ring is short, and a disassembling process thereof is complicated.

SUMMARY OF THE PRESENT INVENTION

Embodiments of the present invention provide a substrate polishing apparatus that can improve polishing efficiency.

Embodiments of the present invention also provide a method of polishing a substrate using the above-described substrate polishing apparatus.

Embodiments of the present invention provide substrate polishing apparatuses including: a substrate supporting member, a polishing unit, and at least one pad supporting member.

A substrate is seated on the substrate supporting member. The polishing unit includes a polishing pad disposed above the substrate supporting member to polish the substrate seated on the substrate supporting member, and a pad driving member moving the polishing pad to vary a relative position of the polishing pad to the substrate supporting member. The pad supporting member is disposed at a side of the substrate supporting member to support a portion of a polishing surface the polishing pad without contacting the substrate when an edge of the substrate seated on the substrate supporting member is polished.

In other embodiments of the present invention, substrate polishing apparatuses include: a bowl unit, a rotatable substrate supporting member, a polishing unit, and at least one pad supporting member.

The bowl unit has an open upper portion. The substrate supporting member on which a substrate is seated is rotatably disposed in the bowl unit. The polishing unit includes a polishing pad disposed above the substrate supporting member to polish the substrate seated on the substrate supporting member in a polishing process, and a pad driving member moving the polishing pad from a central region of the substrate seated on the substrate supporting member to an edge region of the substrate or to a position beyond the edge region of the substrate. The pad supporting member is disposed in the bowl unit, and includes a supporting pad spaced apart from the substrate supporting member and disposed at a side of the substrate supporting member.

In still other embodiments of the present invention, substrate polishing methods are as follows.

A substrate is seated on a substrate supporting member. A polishing pad is disposed above the substrate supporting member. The substrate is pressed and polished by the polishing pad while at least one of the substrate supporting member and the polishing pad is rotated. When the substrate is polished, an edge of the substrate is polished while a portion of the polishing pad without contacting the substrate is supported by a pad supporting member.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the present invention, and are incorporated in and constitute a part of this specification. The drawings illustrate exemplary embodiments of the present invention and, together with the description, serve to explain principles of the present invention. In the figures:

FIG. 1 is a schematic view of a single wafer type polishing system according to an embodiment of the present invention;

FIG. 2 is a perspective view illustrating the wafer polishing unit of FIG. 1;

FIG. 3 is a partial cut-away perspective view illustrating a substrate supporting unit and a bowl unit of FIG. 2;

FIG. 4 is a perspective view illustrating the polishing unit of FIG. 2;

FIG. 5 is a partial cut-away side view illustrating the polishing unit of FIG. 4;

FIG. 6 is a vertical cross-sectional view illustrating a pressing part and a vertical arm part of FIG. 5;

FIG. 7 is a perspective view illustrating the pad supporting member illustrated in FIG. 3;

FIG. 8 is a schematic view illustrating relative positions between the pad supporting member illustrated in FIG. 7, a substrate supporting unit, and a polishing unit;

FIG. 9 is a flowchart illustrating a process in which the wafer polishing part illustrated in FIG. 2 polishes a wafer;

FIG. 10 is a schematic view illustrating a process in which the pad supporting member illustrated in FIG. 8 supports a polishing pad when an edge of a wafer is polished;

FIG. 11 is a schematic view illustrating another example of the pad supporting member illustrated in FIG. 8;

FIG. 12 is a schematic view illustrating a process in which the pad supporting member illustrated in FIG. 11 supports a polishing pad when an edge of a wafer is polished;

FIG. 13 is a schematic view illustrating another example of the pad supporting member illustrated in FIG. 8; and

FIGS. 14A and 14B are schematic views illustrating a height variation of the top surface of the pad supporting member illustrated in FIG. 13 according to positions of a polishing pad when a wafer is polished.

DETAILED DESCRIPTION OF THE EMBODIMENTS

Preferred embodiments of the present invention will be described below in more detail with reference to the accompanying drawings. The present invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art. For example, although a wafer is used as a semiconductor substrate, technical scope and sprite of the present invention is not limited thereto.

FIG. 1 is a schematic view of a single wafer type polishing system according to an embodiment of the present invention.

Referring to FIG. 1, a substrate processing system 2000 according to present invention may include a loading/unloading unit 10, an index robot 20, a buffer unit 30, a main transfer robot 50, a plurality of substrate polishing units 1000, and a control unit 60.

The loading/unloading unit 10 includes a plurality of load ports 11 a, 11 b, 11 c, and 11 d. Although the loading/unloading unit 10 includes four load ports 11 a, 11 b, 11 c, and 11 d in this embodiment, the number of the load ports 11 a, 11 b, 11 c, and 11 d may increase and decrease according to process efficiency and foot print conditions of the substrate processing system 2000.

Front open unified pods (FOUPs) 12 a, 12 b, 12 c, and 12 d in which wafers are received are seated on the load ports 11 a, 11 b, 11 c, and 11 d, respectively. A plurality of slots for receiving the wafers in a horizontal direction with respect to a ground surface are disposed in the respective FOUPs 12 a, 12 b, 12 c, and 12 d. The FOUPs 12 a, 12 b, 12 c, and 12 d receive wafers that have been processed in the respective substrate polishing units 1000 or wafers that will be loaded into the respective substrate polishing units 1000. Hereinafter, for convenience of description, the wafers that have been processed in the respective substrate polishing units 1000 are referred to as processed wafers, and the wafers that are not processed yet are referred to as primitive wafers.

A first transfer path 41 is disposed between the loading/unloading unit 10 and the buffer unit 30. A first transfer rail 42 is disposed in the first transfer path 41. The index robot 20 is disposed on the first transfer rail 42. The index robot 20 moves along the first transfer rail 42 to transfer the wafers between the loading/unloading unit 10 and the buffer unit 30. That is, the index robot 20 takes out at least one primitive wafer from FOUPs 12 a, 12 b, 12 c, and 12 d seated on the loading/unloading unit 10 to load the wafer on the buffer unit 30. Also, the index robot 20 takes out at least one processed wafer from the buffer unit 30 to load the wafer on the FOUPs 12 a, 12 b, 12 c, and 12 d seated on the loading/unloading unit 10.

The buffer unit 30 is disposed at a side of the first transfer path 41. The buffer unit 30 receives the primitive wafers transferred by the index robot 20 and the wafers processed in the substrate polishing units 1000.

The main transfer robot 50 is disposed in a second transfer path 43. A second transfer rail 44 is disposed in the second transfer path 43. The main transfer robot 50 is disposed on the second transfer rail 44. The main transfer robot 50 moves along the second transfer rail 44 to transfer the wafers between the buffer unit 30 and the substrate polishing units 1000. That is, the main transfer robot 50 takes out at least one primitive wafer from the buffer unit 30 to provide the wafer to the substrate polishing units 1000. Also, the main transfer robot 50 loads a wafer processed from the substrate polishing units 1000, that is, a processed wafer on the buffer unit 30.

The substrate polishing units 1000 are disposed at both sides of the second transfer path 43. The respective substrate polishing units 1000 polish and clean the primitive wafer to manufacture the processed wafer. In the substrate polishing units 1000, at least two substrate polishing units face each other with the second transfer path 43 therebetween. In an example of the present invention, when viewed in plan, although two pairs of substrate polishing units 1000 are disposed at both sides of the second transfer path 43 and parallelly disposed along the second transfer path 43, respectively, the number of the substrate polishing units 1000 disposed at both sides of the second transfer path 43 may increase and decrease according to the process efficiency and the foot print conditions of the substrate processing system 2000.

Each of the substrate polishing units 1000 is connected to the control unit 60 to polish and clean the primitive wafer according to the control of the control unit 60. That is, the control unit 60 controls the substrate polishing unit 1000 to control the polishing of each of the substrate polishing units 1000.

Hereinafter, a configuration of the substrate polishing unit 1000 will be described in detail with reference to accompanying drawings.

FIG. 2 is a perspective view illustrating a substrate polishing unit of FIG. 1, and FIG. 3 is a partial cut-away perspective view illustrating a substrate supporting unit and a bowl unit of FIG. 2.

Referring to FIGS. 1 through 3, in the substrate processing system 2000, a polishing process in which a top surface of a wafer 70 is polished and a cleaning process in which a surface of the wafer 70 is cleaned after the polishing process is performed may be sequentially performed within one substrate polishing unit 1000.

Particularly, the substrate polishing unit 1000 may include a substrate supporting unit 100, a bowl unit 200, a polishing unit 300, a pad supporting member 401, first and second process fluid supply units 510 and 520, a brush unit 610, an aerosol unit 620, and a pad conditioning unit 700.

The wafer 70 transferred from the main transfer robot 50 is seated on the substrate supporting unit 100. The substrate supporting unit 100 supports and fixes the wafer 70 during the polishing process and the cleaning process of the wafer 70. The substrate supporting unit 100 may include a spin head 110 on which the wafer 70 is seated, a supporting part 120 supporting the spin head 110, and a spin driving part providing torque.

The spin head 110 has a substantially circular shape when viewed in plan, and a width thereof gradually decreases from a top surface thereof to a bottom surface. In an example of the present invention, the top surface of the spin head 110 supporting the wafer 70 has an area less than that of the wafer 70. Thus, when being viewed from side, an end of the wafer 70 seated on the spin head 110 protrudes outward from a top end of the spin head 110.

The supporting part 120 is disposed below the spin head 110, and connected to the spin driving part. The supporting part 120 has an approximately cylindrical shape, and is coupled to the spin head 110. The spin driving part rotates the supporting part 120, and torque of the supporting part 120 is transmitted to the spin head 110 to rotate the spin head 110. During the polishing and cleaning processes, the spin head 110 fixing the wafer 70 on the top surface is rotated by the torque provided from the spin driving part.

The substrate supporting unit 100 is received into the bowl unit 200. The bowl unit 200 may include first and second process bowls 210 and 220, first and second recovery vats 230 and 240, first and second recovery tubes 251 and 252, and an ascending/descending member 260.

Particularly, the first and second process bowls 210 and 220 surround the substrate supporting unit 100 to provide a space in which the polishing and cleaning processes are performed on the wafer 70. Each of the first, and second process bowls 210 and 220 has an open upper portion through which the spin head 110 is exposed. Although each of the first and second process bowls 210 and 220 has a circular ring shape in this embodiment, the present invention is not limited thereto.

Particularly, the first process bowl 210 may include a sidewall 211, a top plate 212, and a guide part 213. The sidewall 211 may have an approximately circular ring shape to surround the substrate supporting unit 100.

An upper end of the sidewall 211 is connected to the top plate 212. The top plate 212 extends from the sidewall 211 and has a surface inclined upward away from the sidewall 211. The top plate 212 has an approximately circular ring shape. When viewed in plan, the top plate 212 is spaced from the spin head 110 to surround the spin head 110.

The guide part 213 includes first and second guide walls 213 a and 213 b. The first guide wall 213 a protrudes from an inner wall of the sidewall 211 to face the top plate 212. Also, the first guide wall 213 a has a surface inclined downward away from the sidewall 211. The first guide wall 213 a has a circular ring shape. The second guide wall 213 b vertically extends downward from the first guide wall 213 a to face the sidewall 211. The second guide wall 213 b has a circular ring shape. The guide part 213 guides a flow of a process liquid, scattered onto inner surfaces of the sidewall 211 and the top plate 212 of the first process bowl 210 during the polishing process of the wafer 70, toward the first recovery vat 230. \

The second process bowl 220 is disposed outside the first process bowl 210. The second process bowl 220 surrounds the first process bowl 210, and is larger than the first process bowl 210.

Particularly, the second process bowl 220 may include a sidewall 221 and a top plate 222. The sidewall 221 may have an approximately circular ring shape to surround the sidewall 211 of the first process bowl 210. The sidewall 221 is spaced from the sidewall 211 of the first process bowl 210 and connected to the first process bowl 210.

An upper end of the sidewall 221 is connected to the top plate 222. The top plate 222 extends from the sidewall 221 and has a surface inclined upward away from the sidewall 221. The top plate 222 has an approximately circular ring shape. When viewed in plan, the top plate 222 is spaced from the spin head 110 to surround the spin head 110. The top plate 222 is disposed above the top plate 211 of the first process bowl 210. Also, the top plate 222 faces the top plate 211 of the first process bowl 210 and is spaced from the top plate 211 of the first process bowl 210.

The first and second recovery vats 230 and 240 are disposed below the first and second process bowls 210 and 220 to recover the process liquids used for the polishing and cleaning processes. Each of the first and second recovery vats 230 and 240 has an approximately circular ring shape with an open upper portion. Although each of the first and second recovery vats 230 and 240 has the circular ring shape in this embodiment, the present invention is not limited thereto.

The first recovery vat 230 is disposed below the first process bowl 210 to recover the process liquid used for the polishing process. The second recovery vat 240 is disposed below the second process bowl 220 to recover the process liquid used for the cleaning process.

Particularly, the first recovery vat 230 may include a bottom plate 231, a first sidewall 232, a second sidewall 233, and a connection part 234. The bottom plate 231 has an approximately circular ring shape to surround the supporting part 120. In an example of the present invention, the bottom plate 231 has a ‘V’ shaped vertical cross-section to easily discharge the process liquid recovered into the first recovery vat 230. Thus, a recovery flow path 231 a having a ring shape is disposed in the bottom plate 231 to easily discharge and recover the process liquid.

The first sidewall 232 vertically extends from the bottom plate 231 to provide a first recovery space RS1 for recovering the process liquid. The second sidewall 233 is spaced from the first sidewall 232 to face the first sidewall 232. The connection part 234 is connected to the upper end of the first sidewall 232 and the upper end of the second sidewall 233. The connection part 234 has a surface inclined upward from the first sidewall 232 toward the second sidewall 233. The connection part 234 guides the process liquid dropped outside the first recovery space RS1 toward the first recovery space RS1 to introduce the process liquid into the first recovery space RS1.

The second recovery vat 240 is disposed outside the first recovery vat 230. The second recovery vat 240 surrounds the first recovery vat 230 and is spaced from the first recovery vat 230. Particularly, the second recovery vat 240 may include a bottom plate 241, a first sidewall 242, and a second sidewall 243. The bottom plate 241 has an approximately circular ring shape to surround the bottom plate 231 of the first recovery vat 230. In an example of the present invention, the bottom plate 241 has a ‘V’ shaped vertical cross-section to easily discharge the process liquid recovered into the second recovery vat 240. Thus, a recovery flow path 241 a having a ring shape is disposed in the bottom plate 241 to easily discharge and recover the process liquid.

The first and second sidewalls 242 and 243 vertically extend from the bottom plate 241 to provide a second recovery space RS2 for recovering the process liquid. Each of the first and second sidewalls 242 and 243 has a circular ring shape. The first sidewall 242 is disposed between the first and second sidewalls 232 and 233 of the first recovery vat 230 to surround the first sidewall 232 of the first recovery vat 230. The second sidewall 243 of the second recovery vat 240 faces the first sidewall 242 with the bottom plate 241 therebetween to surround the first sidewall 242. The second sidewall 243 of the second recovery vat 240 surrounds the second sidewall 233 of the first recovery vat 230, and an upper end thereof is disposed outside the sidewall 221 of the second process bowl 220.

When the polishing and cleaning processes are performed on the wafer 70, vertical positions between the spin head 110 and the first and second process bowls 210 and 220 are changed according to each process. Thus, the first and second recovery vats 230 and 240 respectively recover process liquids used for processes different from each other.

Particularly, when the polishing process is performed, the spin head 110 is disposed within the first process bowl 210 to perform the polishing process on the wafer 70 within the first process bowl 210. During the polishing process, the wafer 70 is rotated by the rotation of the spin head 110. Thus, during the polishing process, a process liquid sprayed onto the wafer 70 is scattered toward an inner surface of the sidewall 211 and an inner surface of the top plate 212 of the first process bowl 210 due to torque of the wafer 70. The process liquid adhered to the inner surfaces of the sidewall 211 and the top plate 212 of the first process bowl 210 flows along the sidewall 211 and the top plate 212 of the first process bowl 210 in a gravity direction to reach the guide part 213, and then, the process liquid flows along an inner surface of the guide part 213 in the gravity direction and is recovered into the first recovery vat 230.

When the cleaning process is performed after the polishing process is performed, the spin head 110 is disposed below the top plate 222 of the second process bowl 220 and above the first process bowl 210. During the cleaning process, the spin head 110 is rotated. Thus, a process liquid sprayed onto the wafer in the cleaning process is scattered toward inner surfaces of the top plate 222 and the sidewall 221 of the second process bowl 220 and an outer surface of the first process bowl 210. The sidewall 211 of the first process bowl 210 is disposed above the bottom plate 241 of the second recovery vat 240. The process liquid adhered to the outer surface of the first process bowl 210 flows along the outer surface of the first process bowl 210 in the gravity direction and is recovered into the second recovery vat 240. Also, the process liquid adhered to the inner surface of the second process bowl 220 flows along the inner surface of the second process bowl 220 in the gravity direction and is recovered into the second recovery vat 240.

As described above, the first recovery vat 230 recovers the process liquid used for the polishing process, and the second recovery vat 240 recovers the process liquid used for the cleaning process. As a result, since the bowl unit 200 may separately recover the process liquid used for each process performed within the bowl unit 200, the process liquid may be easily reused and recovered.

The first recovery vat 230 is connected to the first recovery tube 251, and the second recovery vat 240 is connected to the second recovery tube 252. The first recovery tube 251 is coupled to the bottom plate 231 of the first recovery vat 230. A first recovery hole 231 b communicating with the first recovery tube 251 is defined in the bottom plate 231 of the first recovery vat 230. The process liquid recovered into the first recovery space RS1 of the first recovery vat 230 is discharged to the outside through the first recovery tube 251 via the first recovery hole 231 b.

Although the bowl unit 200 includes the two process bowls 210 and 220 and the two recovery vats 230 and 240 in this embodiment, the number of the process bowls 210 and 220 and the recovery vats 230 and 240 may increase according to the number of the process liquids used for the polishing and cleaning processes and the number of the process liquids to be separately recovered.

The second recovery tube 252 is coupled to the bottom plate 241 of the second recovery vat 240. A second recovery hole 241 b communicating with the second recovery tube 252 is defined in the bottom plate 241 of the second recovery vat 240. The process liquid recovered into the second recovery space RS2 of the second recovery vat 240 is discharged to the outside through the second recovery tube 252 via the second recovery hole 241 b.

Although the first recovery tube 251 and the second recovery tube 252 are respectively provided in singularity, the number of the first and second recovery tubes 251 and 252 may increase according to sizes and recovery efficiency of the first and second recovery vats 230 and 240.

The vertically movable ascending/descending member 260 is disposed outside the second process bowl 220. The ascending/descending member 260 is coupled to the sidewall 221 of the second process bowl 220 to adjust vertical positions of the first and second process bowls 210 and 220. Particularly, the ascending/descending member 260 may include a bracket 261, a movement shaft 262, and a driver 263. The bracket 261 is fixed to the outer sidewall 221 of the second process bowl 220 and coupled to the movement shaft 262. The movement shaft 262 is connected to the driver 263 and vertically moved by the driver 263.

The first and second process bowls 210 and 220 descend by the ascending/descending member 260 to allow the spin head 110 to protrude upward from the first and second process bowls 210 and 220 when the wafer 70 is seated on the spin head 110 or lifted from the spin head 110. When the first and second process bowls 210 and 220 descend, the first and second sidewalls 232 and 233 and the connection part 234 of the first recovery vat 230 are inserted into a space defined by the sidewall 211 of the first process bowl 210 and the first and second guide walls 213 a and 213 b.

Also, when the polishing and cleaning processes are performed on the wafer 10, the first and second process bowls 210 and 220 ascend and descend by the ascending/descending member 260 to adjust a relative vertical position between the first and second process bowls 210 and 220 and the spin head 110, thereby separately recovering the process liquid used for the polishing process and the process liquid used for the cleaning process.

In this embodiment, although the first and second process bowls 210 and 220 are vertically moved to change the relative vertical position between the first and second process bowls 210 and 220 and the spin head 110 in the substrate polishing unit 1000, the present invention is not limited thereto. For example, the spin head 110 may be vertically moved to change the relative vertical position between the first and second process bowls 210 and 220 and the spin head 110.

The polishing unit 300, the first and second process fluid supply units 510 and 520, the brush unit 610, the aerosol unit 620, and the pad conditioning unit 700 are disposed outside the bowl unit 200.

The polishing unit 300 chemically and mechanically polishes a surface of the wafer 70 fixed to the substrate supporting unit 100 to planarize the surface of the wafer 70.

FIG. 4 is a perspective view illustrating a polishing unit of FIG. 2, and FIG. 5 is a partial cut-away side view illustrating the polishing unit of FIG. 4.

Referring to FIGS. 3, 4 and 5, the polishing unit 300 may include a pressing part 310, a vertical arm part 320, a swing arm part 330, and a driving part 340.

Particularly, the pressing part 310 is disposed above the wafer 70 fixed to the spin head 110 during the polishing process. The pressing part 310 is rotated in a state where it contacts the wafer 70 to polish the wafer 70. While the pressing part 310 polishes the wafer 70, chemical liquid for the wafer 70, that is, slurry is supplied on the top surface of the wafer 70.

The vertical arm part 320 is fixed to the upper end of the pressing part 310. The vertical arm part 320 extends vertically from the top surface of the spin head 110, and is rotated about a longitudinal central axis by torque provided from the driving part 340. Configurations of the pressing part 310 and the vertical arm part 320 will be described later in detail with reference to FIG. 6.

The swing arm part 330 is disposed above the vertical arm part 320. The swing arm part 330 may include a rotation case 331 having a bar shape and a belt-pulley assembly transmitting torque from the driving part 340 to the vertical arm part 320. The rotation case 331 has one side coupled to the vertical arm part 320 and the other side coupled to the driving part 340.

The driving part 340 may include a first driving motor 341 for rotating the swing arm part 330, a second driving motor 342 for rotating the vertical arm part 320, and a vertical movement part 343 for adjusting a vertical position of the pressing part 310.

The first driving motor 341 is coupled to the rotation case 331 to provide the torque to the rotation case 331. The first driving motor 341 may alternately and repeatedly provide clockwise torque and counter-clockwise torque. Thus, the swing arm part 330 is swung by the driving part 340 about a central axis at which it is coupled to the driving part 340. When the polishing process is performed, the pressing part 310 may be horizontally reciprocated in a circular arc shape at an upper portion of the wafer 70 due to the swing operation of the swing arm part 330.

The second driving motor 342 is disposed below the first driving motor 341. The second driving motor 342 provide torque to the belt-pulley assembly. The belt-pulley assembly transmits the torque of the second driving motor 342 to the vertical arm part 320. The belt-pulley assembly is built in the rotation case 331 and may include a driving pulley 332, a driven pulley 333, and a belt 334. The driving pulley 332 is disposed above the first driving motor 341 and coupled to one side of a vertical arm 344 passing through the first driving motor 341. The second driving motor 342 is coupled to the other side of the vertical arm 344.

The driven pulley 333 faces the driving pulley 332. The driven pulley 333 is disposed above the vertical arm part 320 and coupled to the vertical arm part 320. The driving pulley 332 and the driven pulley 333 are connected to each other through the belt 334. The belt 334 is wound around the driving pulley 332 and the driven pulley 333.

The torque of the second driving motor 342 is transmitted to the driving pulley 332 through the vertical arm 344. Thus, the driving pulley 332 is rotated. The torque of the driving pulley 332 is transmitted to the driven pulley 333 through the belt 334. Thus, the driven pulley 333 is rotated. The torque of the driven pulley 333 is transmitted to the vertical arm part 320. Thus, the pressing part 310 and the vertical arm part 320 are rotated.

The vertical movement part 343 is disposed at a rear side of the first driving motor 341 and the second driving motor 342. The vertical movement part 343 may include a ball screw 343 a, a nut 343 b, and a third driving motor 343 c. The ball screw 343 a has a bar shape and is vertically disposed with respect to a ground surface. The nut 343 b is fitted on the ball screw 343 a and fixed to the second driving motor 342. The third driving motor 343 c is disposed below the ball screw 343 a. The third driving motor 343 c may be coupled to the ball screw 343 a to provide clockwise torque and counter-clockwise torque to the ball screw 343 a. The ball screw 343 a is rotated clockwise or counter-clockwise by the third driving motor 343 c. The nut 343 b is vertically moved along the ball screw 343 a by the rotation of the ball screw 343 a. Thus, the second driving motor 342 coupled to the nut 343 b is vertically moved together with the nut 343 b. As the second driving motor 342 is vertically moved, the first driving motor 341 and the swing arm part 330 are vertically moved, and thus, the vertical arm part 320 and the pressing part 310 are vertically moved also.

Although the vertical movement part 343 includes the ball screw 343 a, the nut 343 b, and the third driving motor 343 c to provide a vertical movement force using a linear motor method in this embodiment, the present invention is not limited thereto. For example, the vertical movement part 343 may include a cylinder to provide a vertical movement force.

The first driving motor 341, the second driving motor 342, the ball screw 343 a, the nut 343 b, and the vertical arm 344 are built in a driving case 345. The driving case 345 has a long bar shape in a vertical direction.

Hereinafter, the pressing part 310 and the vertical arm part 320 will now be described in detail with reference to accompanying drawings.

FIG. 6 is a vertical cross-sectional view illustrating a pressing part and a vertical arm part of FIG. 5.

Referring to FIGS. 2, 5 and 6, the vertical arm part 320 is rotated by the torque transmitted from the driving part 340 to rotate the pressing part 310, and provides air to the pressing part 310 to control a pressure for pressing the wafer 70.

Particularly, the vertical arm part 320 may include a housing 321, a rotation shaft 322, a rotary joint 323, first and second bearings 324 a and 324 b, and first and second auxiliary shafts 325 a and 325 b.

The housing 321 has an approximately cylindrical tube shape. An upper end of the housing 321 is inserted into the rotation case 331 of the swing arm part 330. Thus, the housing 321 has the upper end coupled to the rotation case 331 and a lower end coupled to the pressing part 310.

The rotation shaft 322 is disposed within the housing 321 and spaced apart from the housing 321. The rotation shaft 322 extends in the longitudinal direction of the housing 321, and includes an air passage 322 a in a central portion. The air passage 322 a extends in the longitudinal direction of the rotation shaft 322. The rotation shaft 322 is connected to the driven pulley 333, and is rotated about a longitudinal central axis by the torque of the driven pulley 333. The upper end of the rotation shaft 322 is coupled to the rotary joint 323, and the rotary joint 323 supplies air to the air passage 322 a of the rotation shaft 322, and is fixed to the driven pulley 333. The rotary joint 323 includes a rotation part and a fixation part, and the rotation part is fixed to the driven pulley 333 such that the rotation part is rotated by the torque of the driven pulley 333. The fixation part of the rotary joint 323 is connected to an air line 80 for supplying air. Air supplied from the air line 80 is introduced through the rotary joint 323 to the air passage 322 a, and flows along the air passage 322 a to the pressing part 310.

The first and second bearings 324 a and 324 b are disposed between the housing 321 and the rotation shaft 322. The first and second bearings 324 a and 324 b connect the housing 321 to the rotation shaft 322 and support the rotation shaft 322 such that the rotation shaft 322 is stably rotated. The first bearing 324 a is disposed adjacent to the swing arm part 330, and the second bearing 324 b is disposed adjacent to the pressing part 310. Inner races of the first and second bearings 324 a and 324 b are fitted on the rotation shaft 322, and thus rotated together with the rotation shaft 322. Outer races of the first and second bearings 324 a and 324 b are coupled to the housing 321, and thus not rotated when the rotation shaft is rotated. Thus, only the rotation shaft 322 is rotated, and the housing 321 is not rotated.

The first and second auxiliary shafts 325 a and 325 b may be disposed between the rotation shaft 322 and the housing 321. The first auxiliary shaft 325 a is disposed along the inner wall of the housing 321 and protects the housing 321. The second auxiliary shaft 325 b surrounds an outer wall of the rotation shaft 322, and protects the rotation shaft 322.

The pressing part 310 is fixed to the lower end of the rotation shaft 322. The pressing part 310 may include a polishing pad 311, a polishing case 312, upper and lower plates 313 and 314, a pad holder 315, a coupling plate 316, and a bellows 317.

The polishing pad 311 has a plate shape and an approximately circular ring shape. The polishing pad 311 is rotated to polish the wafer in a state where a bottom surface of the polishing pad 311 contacts a top surface of the wafer during the polishing process. The polishing pad 311 has a diameter less than that of the wafer. During the polishing process, the polishing pad 311 is swung by the driving part 340 to polish the wafer. As described above, since the polishing pad 311 has a diameter less than that of the wafer, the polishing unit 300 may locally polish the wafer, and prevent a specific region from being excessively polished.

The polishing case 312 is disposed above the polishing pad 311. The polishing case 312 has an approximately circular ring shape, and includes the upper and lower plates 313 and 314 and the bellows 317 therein. A coupling hole is disposed in the central top surface of the polishing case 312, and the coupling plate 316 is disposed in the coupling hole. The coupling plate 316 is spaced apart from the polishing case 312, and is fixed to the rotation shaft 322 of the vertical arm part 320.

The upper plate 313 is fixed to the bottom surface of the coupling plate 316, and the lower plate 314 is spaced apart from below the upper plate 313. The pad holder 315 is coupled to the bottom surface of the lower plate 314, and the polishing pad 311 is coupled to the bottom surface of the pad holder 315.

The bellows 317 is disposed within a space between the lower plate 314 and the upper plate 313. The bellows 316 is formed of a metallic material, and receives air supplied from the air passage 322 a of the rotation shaft 322. The bellows 316 is vertically expanded and contracted by air pressure. When the polishing process is performed, the bellows 317 is vertically expanded such that the polishing pad 311 closely contacts the wafer by air pressure. When the bellows 316 waits above the substrate supporting unit 100 (refer to FIG. 2), the bellows 316 is contracted by vacuum pressure provided from the air passage 322 a. Thus, the polishing pad 311 is spaced apart from a wafer seated on the substrate supporting unit 100.

As described above, since the pressing part 310 uses the bellows 317 that is expanded and contracted by air pressure, the polishing pad 311 can be tilted according to the top surface shape of the wafer during the polishing process.

Referring again to FIGS. 1 through 3, the pad supporting member 401 is disposed at a side of the substrate supporting unit 100, and the pad supporting member 401 is disposed in the bowl unit 200. When an edge of the wafer 70 is polished, the pad supporting member 401 supports a portion of the polishing pad 311 (refer to FIG. 6) to prevent the polishing pad 311 from being inclined to the outer side of the wafer 70. The configuration of the pad supporting member 401 will be described later in detail with reference to FIGS. 7 and 8.

The first and second process fluid supply units 510 and 520 disposed at the outer side of the bowl unit 200 spray process fluids, needed for the polishing and cleaning processes for the wafer 70, to the wafer 70 fixed to the substrate supporting unit 100. In detail, the first process fluid supply unit 510 is fixed to the sidewall 221 of the second process bowl 220. When the polishing process or the cleaning process is performed, the first process fluid supply unit 510 sprays the process fluid onto the wafer 70 fixed to the spin head 110 to process the wafer 70. In the current embodiment, the process fluid sprayed from the first process fluid supply unit 510 may be process liquid for cleaning or drying the wafer 70 or dry gas for drying the wafer 70.

In an example of the present invention, although the first process fluid supply unit 510 includes four injection nozzles, the number of the injection nozzles may increase or decrease according to the number of the process fluid used for cleaning the wafer 70.

The second process fluid supply unit 520 can be swung, and sprays the process liquid onto the wafer 70 fixed to the spin head 110. Process liquid supplied to the second process fluid supply unit 520 may be slurry. In the polishing process, the slurry may be sprayed to the wafer 70 by a discrete chemical liquid injection member (not shown), not the second process fluid supply unit 520.

The brush unit 610 physically removes foreign substances remaining on the surface of the wafer 70 after the polishing process is performed. The brush unit 610 can be swung and includes a brush pad. The brush pad contacts the surface of the wafer 70 to physically brush foreign substances remaining on the surface of the wafer 70. When the cleaning process is performed, the brush unit 610 disposes the brush pad above the spin head 110 through its swing operation, and rotates the brush pad to clean the wafer 70 fixed to the spin head 110.

The aerosol unit 620 is disposed at a side of the brush unit 610. The aerosol unit 620 sprays the process liquid having fine particles onto the wafer 70 fixed to the spin head 110 at a high pressure to remove the foreign substances remaining on the surface of the wafer 70. For example, the aerosol unit 620 sprays the process liquid in fine particle forms, using supersonic waves. The brush unit 610 is used for removing foreign substances having relatively large particles, and the aerosol unit 620 is used for removing foreign substances having relatively small particles.

The pad conditioning unit 700 cleans and recycles the polishing unit 300 when the polishing unit 300 is disposed within a home port in a standby state. That is, a predetermined polishing pattern is formed on a surface of the polishing pad 311 (refer to FIG. 6) contacting the wafer to improve efficiency of the polishing process. The polishing pattern may be gradually worn by the friction of the wafer when the polishing process is performed on the wafer. Also, the chemical liquids used for the polishing process may be hardened within the polishing pattern. The pad conditioning unit 700 may polish the surface of the polishing pad 311 to recycle the polishing pad 311.

Hereinafter, a configuration of the pad supporting member 401 will now be described in detail with reference to the accompanying drawings.

FIG. 7 is a perspective view illustrating the pad supporting member illustrated in FIG. 3. FIG. 8 is a schematic view illustrating relative positions between the pad supporting member illustrated in FIG. 7, a substrate supporting unit, and a polishing unit.

Referring to FIGS. 2, 7 and 8, the pad supporting member 401 is disposed at a side of the substrate supporting unit 100, and is spaced apart from the substrate supporting unit 100. When an edge of the wafer 70 is polished, a polishing surface of the polishing pad 311, which does not contact the wafer 70, is partially supported by the pad supporting member 401 to prevent the polishing pad 311 from being inclined to the outer side of the wafer 70.

In detail, the pad supporting member 401 may include a supporting body 410 and a pad part 420. The supporting body 410 is fixed to the bottom surface 231 of the bowl unit 200, and has a column shape extending from the bottom surface 231 to the top surface of the bowl unit 200.

The pad part 420 is fixed to the upper end of the supporting body 410, and is adjacent to the spin head 110. The pad part 420 is spaced apart from the spin head 110, and supports a portion of the polishing pad 311 when an edge of the wafer 70 is polished.

The pad part 420 may include a coupling body 421 fixed to the supporting body 410, a supporting plate 422 coupled to the top surface of the coupling body 421, and a supporting pad 424 supporting a portion of the polishing pad 311 when an edge of the wafer 70 is polished. The coupling body 421 is removably coupled to the supporting body 410 by a first screw 430, and has a column shape. The supporting plate 422 is removably coupled to the coupling body 421 by a second screw 423, and has top and side surfaces that are covered with the supporting pad 424.

The supporting pad 424 is formed of synthetic resin, and supports a portion of the polishing pad 311, exposed to the outer side of the wafer 70 without contacting the wafer 70, when an edge of the wafer 70 is polished. For example, the supporting pad 424 has a circular top surface and an area less than that of the polishing pad 311.

When being viewed from side, the top surface of the supporting pad 424 and the top surface of the wafer 70 are disposed on the same line. That is, the top surface of the supporting pad 424 has the same height as that of the wafer 70 fixed to the spin head 110. The supporting pad 424 is disposed on a movement track of the polishing pad 311 or an extension line thereof. That is, the supporting pad 424 is disposed on a movement path where the polishing pad 311 can move through its swing operation. For example, the radius of the polishing pad 311 is equal to or less than the sum of the distance between the supporting pad 424 and the spin head 110 and the width of the supporting pad 424. Thus, the supporting pad 424 can stably support the polishing pad 311.

As such, when an edge of the wafer 70 is polished, the polishing pad 311 is stably supported by the spin head 110 and the supporting pad 424, and thus, the polishing pad 311 is prevented from being inclined to the outer side of the wafer 70. Accordingly, while an edge of the wafer 70 is polished, the substrate polishing unit 1000 can prevent an edge breakage of the wafer 70 and a polishing defect due to inclining of the polishing pad 311, and improve the product yield.

Since the supporting pad 424 and the spin head 110 support the polishing pad 311 when an edge of the wafer 70 is polished, the top surface of the supporting pad 424 is worn by the polishing pad 311. When the wear of the supporting pad 424 is excessive, the top surface of the supporting pad 424 is even lower than the top surface of the wafer 70. As a result, although the supporting pad 424 supports the polishing pad 311 when an edge of the wafer 70 is polished, the polishing pad 311 may be inclined to the outer side of the wafer 70. To prevent the polishing pad 311 from being inclined, the supporting pad 424 is replaced. At this point, the supporting pad 424 may be replaced with a new supporting pad after the supporting pad 424 is removed from the supporting plate 422, or the supporting plate 422 may be removed together with the supporting pad 424 for replacement.

To sense a wear degree of the supporting pad 424, the substrate supporting unit 100 may include a first position sense part 710 that senses the height of the top surface of the supporting pad 424 to output a vertical position value of the top surface of the supporting pad 424. The first position sense part 710 is disposed above the supporting pad 424, and provides the control unit 60 with a vertical position value of the top surface of the supporting pad 424. The control unit 60 checks whether a vertical position value of the supporting pad 424 is out of a preset vertical position range, and determines whether the supporting pad 424 is replaced.

Hereinafter, a process in which the pad supporting member 401 supports the polishing pad 311 when an edge of the wafer 70 is polished will now be described in detail with reference to the accompanying drawings.

FIG. 9 is a flowchart illustrating a process in which the substrate polishing part illustrated in FIG. 2 polishes a wafer. FIG. 10 is a schematic view illustrating a process in which the pad supporting member illustrated in FIG. 8 supports a polishing pad when an edge of a wafer is polished.

Referring to FIGS. 9 and 10, in operation S110, the wafer 70 is seated on the top surface of the spin head 110.

Subsequently, in operation S120, the polishing pad 311 is disposed on the top surface of the wafer 70.

Subsequently, in operation S130, the spin head 110 is rotated to rotate the wafer 70, and simultaneously, the polishing pad 311 rotates and presses the wafer 70 to polish the wafer 70. When the wafer 70 is polished, slurry is supplied to the top surface of the wafer 70, and the polishing pad 311 polishing the wafer 70 is rotated and swung to vary a relative position to the wafer 70.

When the wafer 70 is polished, the polishing pad 311 moves to an edge of the wafer 70 through its swing operation to polish the edge of the wafer 70. At this point, the top surface of the supporting pad 424 supports a portion of the polishing pad 311 without contacting the wafer 70, that is, a portion of the polishing pad 311 exposed to the outer side of the wafer 70. Accordingly, the pad supporting member 401 prevents the polishing pad 311 from being inclined to the outer side of the wafer 70.

FIG. 11 is a schematic view illustrating another example of the pad supporting member illustrated in FIG. 8. FIG. 12 is a schematic view illustrating a process in which the pad supporting member illustrated in FIG. 11 supports a polishing pad when an edge of a wafer is polished.

Referring to FIGS. 11 and 12, a pad supporting member 402 may include the supporting body 410, the pad part 420, and a position adjustment part 440. The pad supporting member 402 is the same in configuration as the pad supporting member 401 illustrated in FIG. 8, except the position adjustment part 440. Thus, the same components as those of the pad supporting member 401 illustrated in FIG. 8 are denoted by reference numerals, and detailed descriptions thereof will be omitted.

The position adjustment part 440 is fixed to the lower portion of the supporting body 410, and vertically moves the supporting body 410 to adjust the top surface of the pad part 420, that is, the height of the top surface of the supporting pad 424. In the current embodiment, the position adjustment part 440 is constituted by a cylinder, but may be constituted by a driving motor.

The position adjustment part 440 may be connected to the control unit 60 and be controlled by the control unit 60. That is, the control unit 60 receives a vertical position value of the top surface of the supporting pad 424, which is a value output from the first position sense part 710, and controls the position adjustment part 440 according to the received vertical position value to adjust the height of the top surface of the supporting pad 424 to be the same as a preset height, for example, the same as the height of the top surface of the wafer 70.

FIG. 13 is a schematic view illustrating another example of the pad supporting member illustrated in FIG. 8.

Referring to FIG. 13, a pad supporting member 403 is disposed at a side of the substrate supporting unit 100, and is spaced apart from the substrate supporting unit 100. When an edge of the wafer 70 is polished, a polishing surface of the polishing pad 311, which does not contact the wafer 70, is partially supported by the pad supporting member 403 to prevent the polishing pad 311 from being inclined to the outer side of the wafer 70.

In detail, the pad supporting member 403 may include a supporting body 450, a pad part 460, a connection part 470, and a position adjustment part 480. The supporting body 450 is fixed to the bottom surface 231 of the bowl unit 200 (refer to FIG. 3), and has a column shape extending from the bottom surface 231 to the top surface of the bowl unit 200.

The connection part 470 is coupled to the upper end of the supporting body 450 such that the connection part 470 is vertically movable, and the pad part 460 is fixed to the upper end of the connection part 470. The pad part 460 is adjacently spaced apart from the spin head 110, and supports a portion of the polishing pad 311 when an edge of the wafer 70 is polished.

The pad part 460 may include a supporting plate 461 coupled to the top surface of the connection part 470, and a supporting pad 462 supporting a portion of the polishing pad 311 when an edge of the wafer 70 is polished. The upper and side surfaces of the supporting plate 461 may be covered with the supporting pad 462.

The supporting pad 462 is formed of synthetic resin, and supports a portion of the polishing pad 311, exposed to the outer side of the wafer 70 without contacting the wafer 70, when an edge of the wafer 70 is polished. For example, the supporting pad 462 has a circular top surface and an area less than that of the polishing pad 311.

The supporting pad 462 is disposed on a movement track of the polishing pad 311 or an extension line thereof. That is, the supporting pad 462 is disposed on a movement path where the polishing pad 311 can move through its swing operation. For example, the radius of the polishing pad 311 is equal to or less than the sum of the distance between the supporting pad 462 and the spin head 110 and the width of the supporting pad 462. Thus, the supporting pad 462 can stably support the polishing pad 311.

As such, when an edge of the wafer 70 is polished, the polishing pad 311 is stably supported by the spin head 110 and the supporting pad 462, and thus, the polishing pad 311 is prevented from being inclined to the outer side of the wafer 70. Accordingly, while an edge of the wafer 70 is polished, the substrate polishing unit 1000 can prevent an edge breakage of the wafer 70 and a polishing defect due to inclining of the polishing pad 311, and improve the product yield.

The supporting pad 462 is removably coupled to the supporting plate 461. Thus, when the supporting pad 462 is worn a predetermined amount or greater by the polishing pad 311, the supporting pad 462 can be removed and replaced.

The position adjustment part 480 is disposed between the supporting plate 461 and the supporting body 450. The position adjustment part 480 is contracted and expanded by air pressure to adjust the vertical position of the supporting pad 462.

A second position sense part 720 may be disposed between the substrate supporting unit 100 and the pad supporting member 403. The second position sense part 720 senses a relative position of the polishing pad 311 to the substrate supporting unit 100 to provide a horizontal position value of the polishing pad 311 to the control unit 60. In the current embodiment, the second position sense part 720 is discretely disposed at a side of the pad supporting member 403, but may be disposed in the polishing unit 300.

The control unit 60 controls the position adjustment part 480 according to a received horizontal position value of the polishing pad 311 and a vertical position value of the top surface of the supporting pad 462 to adjust the position of the top surface of the supporting pad 462.

FIGS. 14A and 14B are schematic views illustrating a height variation of the top surface of the pad supporting member illustrated in FIG. 13 according to positions of a polishing pad when a wafer is polished.

Referring to FIG. 14A, when the polishing pad 311 is disposed in a region except the edge of the wafer 70, the position adjustment part 480 are contracted to move the supporting pad 462 downward. As a result, the top surface of the supporting pad 462 is lower than the top surface of the wafer 70.

Referring to FIG. 14B, when the polishing pad 311 is disposed in the edge of the wafer 70, the position adjustment part 480 are expanded to move the supporting pad 462 upward. As a result, the top surface of the supporting pad 462 partially contacts the polishing surface of the polishing pad 311 exposed to the outer side of the wafer 70, to support the polishing pad 311.

According to the above-described embodiments, when an edge of a wafer is polished, the pad supporting member partially supports the polishing pad exposed to the outer side of the wafer, and thus, the pad supporting member prevents the polishing pad from being inclined to the outer side of the wafer while the edge of the wafer is polished. Accordingly, the substrate polishing unit improves polishing efficiency, and prevents the breakage of a substrate during a polishing process.

The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments, which fall within the true spirit and scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description. 

1. A substrate polishing apparatus comprising: a substrate supporting member on which a substrate is seated; a polishing unit including a polishing pad disposed above the substrate supporting member to polish the substrate seated on the substrate supporting member, and a pad driving member moving the polishing pad to vary a relative position of the polishing pad to the substrate supporting member; and at least one pad supporting member disposed at a side of the substrate supporting member to support a portion of a polishing surface the polishing pad without contacting the substrate when an edge of the substrate seated on the substrate supporting member is polished.
 2. The substrate polishing apparatus of claim 1, further comprising a substrate driving member rotating the substrate supporting member about a central axis thereof.
 3. The substrate polishing apparatus of claim 2, wherein the polishing surface of the polishing pad has an area less than that of a top surface of the substrate supporting member.
 4. The substrate polishing apparatus of claim 3, wherein the pad driving member swings the polishing pad.
 5. The substrate polishing apparatus of claim 3, wherein the pad driving member comprises: a vertical arm connected to the polishing pad and vertically extending and rotating about a central axis thereof to rotate the polishing pad; a swingable swing arm connected to an upper end of the vertical arm to swing the polishing pad; and a driving part connected to an end of the swing arm and providing torque for swing the swing arm to the swing arm and providing torque for rotating the vertical arm to the vertical arm through the swing arm.
 6. The substrate polishing apparatus of claim 4, wherein the pad supporting member is disposed on a movement track of the polishing pad or on an extension line of the movement track.
 7. The substrate polishing apparatus of claim 6, wherein the movement track has an arc shape.
 8. The substrate polishing apparatus of claim 1, further comprising a bowl unit having an open upper portion and an inside where the pad supporting member is disposed.
 9. The substrate polishing apparatus of claim 8, wherein the pad supporting member comprises: a supporting body disposed at a side of the substrate supporting member; and a supporting pad coupled to an upper portion of the supporting body and spaced apart from the substrate supporting member and supporting the polishing pad when an edge of the substrate is polished.
 10. The substrate polishing apparatus of claim 9, wherein the supporting pad is removably coupled to the supporting body.
 11. The substrate polishing apparatus of claim 9, further comprising a first position sense part sensing a height of the pad supporting member to output a position value of a top surface of the supporting pad to sense a wear degree of the supporting pad.
 12. The substrate polishing apparatus of claim 11, wherein the supporting body is fixed to a bottom surface of the bowl unit.
 13. The substrate polishing apparatus of claim 9, wherein the pad supporting member further comprises a position adjustment part vertically moving the supporting body or the supporting pad to adjust a vertical position of the supporting pad.
 14. The substrate polishing apparatus of claim 13, wherein the position adjustment part comprises a driving motor or a cylinder, and the driving motor or the cylinder is fixed to a lower portion of the supporting body.
 15. The substrate polishing apparatus of claim 13, further comprising: a first position sense part sensing a height of the pad supporting member to output a vertical position value of a top surface of the supporting pad to sense a wear degree of the supporting pad; and a control unit receiving the vertical position value of the top surface of the supporting pad output from the first position sense part, and controlling the position adjustment part according to the received vertical position value to adjust a position of the top surface of the supporting pad.
 16. The substrate polishing apparatus of claim 15, further comprising a second position sense part sensing a relative horizontal position of the polishing pad to the substrate supporting member to provide a horizontal position value of the polishing pad to the control unit
 17. The substrate polishing apparatus of claim 16, wherein the control unit controls the position adjustment part according to the received horizontal position value of the polishing pad and the vertical position value of the top surface of the supporting pad to adjust the position of the upper surface of the supporting pad.
 18. The substrate polishing apparatus of claim 17, wherein the position adjustment part comprises a bellows expanded and contracted by air pressure, and the bellows is disposed between the supporting body and the supporting pad and adjusts a vertical position of the supporting pad through contraction and expansion.
 19. The substrate polishing apparatus of claim 9, wherein the supporting body has a column shape, and a top surface of the supporting pad has an area less than that of the polishing surface of the polishing pad.
 20. The substrate polishing apparatus of claim 9, wherein the polishing pad has a radius that is equal to or less than a sum of a distance between the supporting pad and the substrate supporting member and a width of the supporting pad.
 21. The substrate polishing apparatus of claim 9, wherein the supporting pad has a circular top surface, and the polishing pad has a radius that is equal to or less than a sum of a distance between the supporting pad and the substrate supporting member and a width of the supporting pad.
 22. The substrate polishing apparatus of claim 9, wherein the supporting pad is formed of synthetic resin.
 23. A substrate polishing apparatus comprising: a bowl unit having an open upper portion; a rotatable substrate supporting member on which a substrate is seated, and disposed in the bowl unit; a polishing unit including a polishing pad disposed above the substrate supporting member to polish the substrate seated on the substrate supporting member in a polishing process, and a pad driving member moving the polishing pad from a central region of the substrate seated on the substrate supporting member to an edge region of the substrate or to a position beyond the edge region of the substrate; and a pad supporting member disposed in the bowl unit and including a supporting pad spaced apart from the substrate supporting member and disposed at a side of the substrate supporting member
 24. The substrate polishing apparatus of claim 23, wherein the pad supporting member comprises: a supporting body disposed at a side of the substrate supporting member; and a supporting pad coupled to an upper portion of the supporting body and spaced apart from the substrate supporting member and supporting the polishing pad when an edge of the substrate is polished.
 25. The substrate polishing apparatus of claim 24, wherein the pad supporting member comprises a position adjustment part coupled to the supporting body or the supporting pad and vertically moving the supporting body or the supporting pad to adjust a vertical position of the supporting pad.
 26. The substrate polishing apparatus of claim 23, wherein the polishing pad has a radius that is equal to or less than a sum of a distance between the supporting pad and the substrate supporting member and a width of the supporting pad.
 27. A substrate polishing method comprising: seating a substrate on a substrate supporting member; disposing a polishing pad above the substrate supporting member; and pressing and polishing, by the polishing pad, the substrate while at least one of the substrate supporting member and the polishing pad is rotated, wherein the polishing of the substrate includes polishing an edge of the substrate while a portion of the polishing pad without contacting the substrate is supported by a pad supporting member.
 28. The substrate polishing method of claim 27, wherein the polishing pad has a diameter less than that of the substrate, and the polishing pad moves from a central region of the substrate to the edge of the substrate to polish the substrate.
 29. The substrate polishing method of claim 28, wherein the polishing pad swings on an upper portion of the substrate to polish the substrate.
 30. The substrate polishing method of claim 27, wherein a top surface of the pad supporting member and a top surface of the substrate contacting the polishing pad are disposed on the same line when being viewed from side.
 31. The substrate polishing method of claim 30, wherein the polishing of the edge of the substrate comprises: sensing a vertical position of the top surface of the pad supporting member; and adjusting a vertical position of a top surface of a horizontal adjustment part according to a value of the sensed vertical position such that, when being viewed from side, the top surface of the pad supporting member and the top surface of the substrate are disposed on the same line.
 32. The substrate polishing method of claim 31, wherein the sensing of the vertical position of the top surface of the pad supporting member and the adjusting of the vertical position of the top surface of the pad supporting member are performed while the polishing pad polishes the edge of the substrate.
 33. The substrate polishing method of claim 27, wherein the polishing of the substrate comprises: sensing a horizontal position of the polishing pad on the substrate; and adjusting a vertical position of a top surface of the pad supporting member according to a value of the horizontal position of the polishing pad
 34. The substrate polishing method of claim 33, wherein the adjusting of the vertical position of the top surface of the pad supporting member comprises: moving the top surface of the pad supporting member downward to dispose, when being viewed from side, the top surface of the pad supporting member below a top surface of the substrate when the polishing pad is disposed in a region except for the edge of the substrate; and moving the top surface of the pad supporting member upward such that the pad supporting member supports a portion of a polishing surface of the polishing pad without contacting the substrate when the polishing pad is disposed at the edge of the substrate.
 35. The substrate polishing method of claim 34, wherein the moving of the top surface of the pad supporting member upward comprises: sensing a vertical position of a top surface of a horizontal adjustment part; and adjusting the vertical position of the top surface of the pad supporting member such that, when being viewed from side, the top surface of the pad supporting member and the top surface of the substrate are disposed on the same line. 